<template>
  <!-- 底部 -->
  <div class="my-footer">
    <!-- 全选 -->
    <div class="custom-control custom-checkbox" >
      <input type="checkbox" class="custom-control-input" id="footerCheck" v-model="isAll">
      <label class="custom-control-label" for="footerCheck" >全选</label>
    </div>
    <!-- 合计 -->
    <!-- 思路先用filder筛选出goods_state为true的再对为true的对象中的count数量进行统计  -->
    <div>
      <span>合计:</span>
      <span class="price">¥ {{Allprice}} </span>
    </div>
    <!-- 按钮 -->
    <button type="button" class="footer-btn btn btn-primary">结算  ({{Allnumber}}) </button>
  </div>
</template>

<script>
export default {
      props:{
        list:{
          type:Array,
          required:true
     }
   },
   computed:{
     isAll: {
        get() {
          return this.list.every(item => item.goods_state === true)
        },
        set(val) {
          this.list.forEach(item => item.goods_state = val)
        },
     },
      Allnumber() {
        // 用reduce求和筛选的出goods_state为true的新数组，新数组中求和他的goods_count长度
          return (this.list.filter(item => item.goods_state === true)).reduce((prev,item) => prev + item.goods_count,0)
       },
       Allprice(){
          return (this.list.filter(item => item.goods_state)).reduce((prev,item) => prev + item.goods_count * item.goods_price,0)
       }
   }
}
</script>

<style lang="less" scoped>
.my-footer {
  position: fixed;
  z-index: 2;
  bottom: 0;
  width: 100%;
  height: 50px;
  border-top: 1px solid #ccc;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 10px;
  background: #fff;

  .price {
    color: red;
    font-weight: bold;
    font-size: 15px;
  }
  .footer-btn {
    min-width: 80px;
    height: 30px;
    line-height: 30px;
    border-radius: 25px;
    padding: 0;
  }
}
</style>